1. Field of the Invention
The present invention relates to a chemical process and an apparatus for tissue processing, which are simplified by using only two different solutions in two separate reaction modules.
2. Description of the Related Art
Processes for tissue processing have been described which require use of more than two different solutions, products useful therein, and systems for tissue processing (see WO 99/09390, WO 01/44783, and WO 01/44784). They addressed the need for rapid tissue processing. It is now shown that (i) a non-aqueous admixture and (ii) a wax solution in two separate reaction modules are sufficient to process tissue quickly and completely.
In contrast to the invention disclosed herein, Boon et al. (Eur. J. Morphol. 33:349-358, 1995) use an isopropanol solution and a paraffin wax solution in two separate reaction chambers, each subject to vacuum and microwave heating, to process tissue specimens for histology. Their system requires that tissue specimens be fixed prior to processing and uses a turntable to distribute microwave energy. In addition, the glass container holding the tissue specimens also adsorbs microwave energy and transfers heat to the solution therein.
Milestone (WO 98/05938) provides another alternative for tissue processing in at least three steps: fixing the tissue specimen, simultaneously dehydrating and clearing with dehydrating agent and an essentially lipophilic agent, and impregnating the tissue specimen. Microwave heating is used in the first two steps and elevated pressure is used during the dehydrating/clearing step. The tissue specimen is dried by heating and reduced pressure, and then it is impregnated under vacuum or, alternatively, by applying a cycle of moderate pressure and moderate vacuum.
The cost of automated instruments for tissue processing and expenditures for their operation need to be decreased for efficient delivery of healthcare. Better diagnosis also raises the confidence of patients that their treatment will be based on reliable information and they can be followed by their physicians in a timely manner. A reduction in equipment costs may allow the purchase of additional instruments so they may be distributed across the service area (e.g., primary care facilities). Tissues may be processed locally in such a distributive network and then transported to a specialized pathology facility for analysis. In physician offices and smaller clinics, space is precious and decreasing the size of the automated instrument will allow its placement in a cramped room.
For example, reducing the number of modules in a tissue processing system to two (i.e., one heating module and one vacuum module) will eliminate duplication of mechanical and electrical components and shrink the size of the system. It will be more affordable and easier to place in the laboratory. Fewer chemical compositions will need to be stocked and training personnel in use of the system will be eased.
Processes and systems for tissue processing are now described which use fewer chemical compositions in the former and fewer mechanical and electrical components in the latter as compared to our previously described inventions. This is an improvement over the processes and systems disclosed in U.S. Pat. Nos. 6,207,408 and 6,793,890.
Other advantages of the invention are discussed below or would be apparent to a person skilled in the art from that discussion.